The fast-moving storm has already curtailed production at more than 71 percent of U.S. Gulf of Mexico offshore platforms, nearly three times the number affected by Harvey, which packed more of a punch when it hit the Texas coast.

Nate could become a Category 2 storm, the second weakest on a five-category scale used by meteorologists, with winds of up to 110 miles per hour (177 km per hour) before landfall later on Saturday, the National Hurricane Center said.

Its track takes it closer to offshore production unlike Harvey, whose impact was greatest on refining centers.

Colby Goatley, a meteorologist at Weather Decision Technologies Inc, said his firm is helping about 10 drilling rig operators chart a course away from Nate, which is producing up to 30-foot (9.1-meter) waves near its center, he said.

“Rigs on the eastern side (of Nate) are racing westward to get on that more favorable side,” he said. A few rig operators are heading further east to avoid winds that are strongest to the east of the storm’s eye.

Weather Decision is expecting tropical storm-force winds to last about 12 hours, Goatley said, a relatively short period that will help offshore producers return to full operations quickly and rigs return to their drilling sites.

Nate is converging on refineries that remained in operation during Harvey, with Phillips 66’s Alliance plant, Valero Energy Corp’s Meraux facility, and PBF Energy’s Chalmette refinery closest to its current track. Chevron Corp’s Pascagoula, Miss., plant also is within the impact zone.

Phillips 66 confirmed that it shut its 247,000-barrel-per-day Alliance refinery on Saturday. Alliance, which is 25 miles (40 km) south of New Orleans, is close to the path Nate is forecast to take over southeastern Louisiana.

Valero and PBF Energy were planning to keep running during Nate’s passage, according to sources familiar with those operations. Those two plants and Alliance account for about 3 percent of U.S. refining capacity.

Chevron said it has made preliminary preparations for the storm, including securing loose equipment and positioning standby generators. A spokesman declined to comment further on the operation. The Pascagoula plant accounts for about 2 percent of U.S. refining capacity.